Page 10
– Bulletin 100-50-5.1
The local controller is listed as
c
. To view a different
controller on the display network, rotate the SELECT knob to
CAdr
and then press and release the knob. Rotate the knob to
select the address of a controller. Once the address is selected
it will take a moment to boot up. Setpoints on any control-
ler can be changed as described in
Section 3 - Setpoint Menu
Operation
.
The
CAdr
of a Superheat Control without display can also be
set through Modbus.
Multiple Controllers
The
CAdr
of a Superheat Control without display, display
address 3-99, must be set individually using a Kelvin II
d
or
through Modbus.
Three or more controllers can be networked through the
use of a special junction box that is easily fabricated. The
controllers are wired to the junction box using the RJ-45 jacks
and Cat 5 Ethernet cable (see
Figure 3 - Display Network-
ing
). Superheat Controls can connect to any junction box
ports. Unpowered remote display units (Kelvin II
d
) should be
connected to specially wired ports designated for the remote
display, shown in red in Figure 4.
Junction Box Fabrication
Category 5E junction boxes can be sourced from L-com.
•
Model SMM45-6W can connect 6 controllers (1 remote dis-
play and 5 Superheat controllers with or without displays).
•
Model SMM45-12W can connect 12 controllers.
Junction boxes may be daisy-chained to extend the number of
Kelvin II Controls on the network. Kelvin II
d
remote displays,
being unpowered, must be connected to an energized port (red
Figure 3 - Display Networking
Figure 4 - Wiring the Powered (Red) Jacks
Kelvin IId
Superheat Control
with or without
Display
Superheat Control
with or without
Display
Superheat Control
with or without
Display
Superheat Control
with or without
Display
Junction Box
jacks in Figure 3), with a powered controller plugged into the
other red jack. If all the networked controllers are powered
models, no special wiring (red jacks) is necessary.
To wire a junction box, punch down all blue and blue/white
wires. To wire a pair of energized (red) jacks, punch down
brown and brown/white wires between 2 jacks. See Figure 4.
6. Controller Networking
The Sporlan Superheat Control can communicate with a
Modbus RTU communication master or BACnet MSTP mas-
ter via RS485. See
Appendix J - Modbus Memory Map
and
Appendix K - BACnet Map
.
The serial settings are:
•
9600 baud (default), 19200 baud, 38400 baud
•
8 data bits
•
1 stop bit
•
Even parity (default), odd parity, no parity
Scaling
For better precision, scaling is used for Bar or Celsius units.
PSI and Fahrenheit are whole numbers and have no scaling.
Celsius values transferred via Modbus are 10X. For example,
a value of 45 will be transferred for the superheat when the
actual superheat temperature is 4.5°C. Remember this when
changing a setpoint.
Bar values transferred via Modbus are 100X. For example a
value of 1034 will be transferred for the Maximum Operating
Pressure when the actual pressure is 10.34 Bar. Remember
this when changing a setpoint.
